in your case you donīt need 105 dB,
i think even 100 dB would be extrem loud.
...
in your case a Schalmei sathorn with one aktive sub with sat crossover
for your tube would be enough in your small room

and

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horns would be nice, if only for the mids and up in a 2 way with a large woofer....2 18" pro subs on Hframe or something like that is what id try myeslf, with a decent large mid horn. but thats for ultimate efficiency.

HM, wish I could read german! Maybe, as you say, I don't need extreme efficiency. Interestingly, I had thought about something similar to what you and moondog suggest. I had been wondering about a tubed amp for everything from 100-200Hz or so and up, and a solid state amp for the bottom end? Then integrate a large woofer/sub into whatever cabinet I come up with and drive that with a kind of bi-amped setup? E.g. OB with a sub? Would that end up giving me more options at potentially lower cost? Hmmm. I've been wanting to play with some tripath chips I have b/c of their apparent efficiency.

Anyway, I'm someone who doesn't need earth shaking and extremely low bass (this isn't a HT setup). Tight, well defined and controlled, yes. I built a pair of BD Pipes using 4.5" cheap drivers, and I only miss some bass response.

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your amp need a poti where you can put 0,0001 Watt.

Sorry but I don't understand. What is a "poti?" The .0001 watt capability would make my life MUCH easier as I wouldn't need to work out potentially tricky topologies.

Godzilla, a BIB with the BOFU is certainly a possibility but can you give me an idea of the efficiency? The driver is something like 90dB free air (I think).

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Jensen Imperials? Big, big, speakers, little tiny amp?

DECWARE Imperial Folded Horn

I've read about these. Is the scantilly clad woman smoking a cigarette an integral part of the performance? If so, not sure about the WAF. Besides, wouldn't fit in my 13x15 room. Though if I went mono...

>>> Godzilla, a BIB with the BOFU is certainly a possibility but can you give me an idea of the efficiency? The driver is something like 90dB free air (I think).

You would get about 90db per watt but it will go very low into the bass. If you built a BIB using the 12lta you would be at around 97db per watt.

As far as 8" drivers the BOFU (B20) is about as efficient as i've heard. But it's no longer available (at Parts Express anyway) and has been replaced with an even less expensive 8" driver by GRS. My subjective opinion of the GRS is that it's 'as efficient' but thinner sounding than the BOFU.

i think your room maybe slightly small for something that big. i have a similar room, and i dont think i could tolerate anything bigger than a 8-10" speaker before the speakers were so close together i was practically listening in mono.....

??? Horns you can cram in the corners without penalty unlike simple cone/dome speakers and if built to maximize corner space, then a much bigger cab can be had before it impedes on the room/seating position too much same as a corner china cabinet.

Hmm, too small a room, too short a listening distance is when you need to resort to headphones.

105 dB transient peak capability isn't extremely loud unless you are listening to highly compressed music, so assuming he wants to at least occasionally listen to a low/no compressed recording that can have up to 30 dB of dynamic headroom (75 dB average SPL) or louder than he would typically listen to a prime-time TV show (70-75 dB SPL), 105 dB isn't an 'overkill' recommendation.

Guess we will have to 'agree to disagree'.

GM

__________________Loud is Beautiful if it's Clean! As always though, the usual disclaimers apply to this post's contents.

Understood, short of the Imperial, Klipschorn or similar high acoustic efficiency alignment, you won't get HE below ~80 Hz without a loss of proper transient response (''tightness', etc.), i.e. the average male's lower vocal limit and as you note you can always add a sub system at a later date.

There's probably a chart somewhere, but don't recall seeing one, or if I did I didn't pay any attention to it since it has no real meaning due to being a variable based on the driver's Fs, Qes, Vas specs.

If you mean acoustic radiation impedance that's a function of a driver's volume displacement (Vd), i.e. effective cone area (Sd) times linear excursion (Xmax), then there's a formula, but would have to look it up later.

In small rooms there's lots to said for a mono system, especially if it's corner loaded with the seating position oriented to on-axis. This is a good choice for a 2.1 system with the mono 'sub' in the corner and the mains along the side walls.

These beautifully finished Altec A7-500 theater mains with an electronically EQ'd Karlson is one such system, though in a small room, one of Hm's smaller BLHs or similar might suffice for the mains depending on the driver(s) used and the 'sub' system could be any number of choices from a bass dipole 'infinite' line array to tapped pipe (TP) or horn (TH) to whatever, though a dipole array of low Fs, Qts drivers is technically your best choice short of a huge FLH.

Hello,
"don't understand. What is a "poti?" The .0001 watt capability"
your volume control, if you need normal householt level, 90% of the time,
normal speech 60-65 dB how much watt do you need with a 105 dB1m1W
in your case, volume control (Potentiometer) and amp wonīt get it.
I donīt know an amp which work around 0,0001 Watt, may be with a Poti for 10000$ :-)).

The Aurasound you link to is exactly the driver that got me thinking line array was within reach. They are 82dB though, so not sure they'd get me the efficiency I seek even in a line array. The bipole/dipole idea had me intrigued, so I looked at the twitterspeak link in post 12. $0.69/driver made that seem possible too.

The trouble for me, and the reason for this post, is that I have limited experience with speakers - I've only really listened to typical multi-way boxes and single driver/fullrangers. So I hoped to get some insight into the pros and cons of different approaches to very high efficiency speakers. I'm certainly getting that.

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I donīt know an amp which work around 0,0001 Watt, may be with a Poti for 10000$ :-)).

HM, I thought you were suggesting something that would work around micro-wattage environment. That's not my need, so no worries. As for your designs, I've been taking a look and am intrigued.